The chemistry and metabolism of membrane-bound and circulation sialoglycoconjugates will be investigated during chemical carcinogenesis in rats subjected to nutritional stress. The development of chemically induced hepatomas and mammary carcinomas will be modulated by the level and degree of unsaturation of dietary lipids both in the presence and in the absence of added antioxidants. The chemical studies will focus mainly on the investigation of the properties, chemical composition and structure of sialic acid-rich glycoproteins. The enzymological studies will focus mainly on the enzymes responsible for the activation, transfer, and hydrolysis of sialic acids (i.e., CMP-NANA synthetase, sialyl transferase and neuraminidase). These studies will be conducted utilizing serum and various membrane fracions from liver and mammary glands of normal, preneoplastic and cancer-bearing rats. The principal aims of this research are 1) to elucidate the molecular alterations of membrane-bound and circulating sialoglycoproteins, 2) to define the enzymological derangements underlying these alterations, and 3) to establish the effect of the nutritional stress on these biochemical parameters in rats undergoing chemical carcinogenesis.